1. Field of the Invention
The present invention relates generally to a disk drive including an air bearing slider including pressurized side pads with forward and trailing shallow etched surfaces.
2. Description of the Prior Art
The typical hard disk drive includes a head disk assembly (HDA) and a printed circuit board assembly (PCBA) attached to a disk drive base of the HDA. The head disk assembly includes at least one magnetic disk, a spindle motor for rotating the disk, and a head stack assembly (HSA). The spindle motor includes a spindle motor hub that is rotatably attached to the disk drive base. The hub has an outer hub flange that supports a lowermost disk. Additional disks may be stacked and separated with annular disk spacers that are disposed about the hub. The head stack assembly has an actuator assembly including at least one air bearing slider or head, typically several, for reading and writing data to and from the disk. Each air bearing slider includes a magnetic transducer. An example of a slider is disclosed in U.S. Pat. No. 5,473,485 (incorporated herein by reference) that describes a tri-pad slider where a center pad contains a transducer. The printed circuit board assembly includes a servo control system in the form of a disk controller for generating servo control signals. The head stack assembly is controllably positioned in response to the generated servo control signals from the disk controller. In so doing, the attached heads are moved relative to tracks disposed upon the disk.
The head stack assembly includes an actuator assembly, at least one head gimbal assembly, and a flex circuit cable assembly. A conventional “rotary” or “swing-type” actuator assembly typically includes an actuator body that has a bore and a pivot bearing cartridge engaged within the bore for facilitating the actuator body to rotate between limited positions. The actuator assembly further includes a coil portion that extends from one side of the actuator body to interact with one or more permanent magnets to form a voice coil motor. One or more actuator arms extend from an opposite side of the actuator body. A head gimbal assembly includes an air bearing slider that is attached to a suspension with a gimbal. Head gimbal assemblies are distally attached to each of the actuator arms. The head gimbal assemblies and the flex circuit cable assembly are attached to the actuator assembly.
A problem that arises with such prior art slider designs is that debris in the form of particulate matter and dense fluids, such as lubricants, may tend to accumulate at various locations downstream of the various air bearing surfaces that may be disposed about the slider. This is because the structures supporting the air bearing surfaces may tend to promote a vacuum effect with air expanding immediately downstream of such air bearing surfaces. The accumulated debris negatively impacts the aerodynamic characteristics of the slider because the debris results in a change of the geometry of the slider. In addition, after accumulating, a portion of the debris may become dislodged. In this regard, the accumulation and dislodgement of the debris may be non-symmetrical with respect to the slider further negatively impacting the aerodynamic characteristics of the slider. Moreover, dislodged debris may become attached to the downstream center pad further exasperating the impact to aerodynamic characteristics of the slider. Such changes to the aerodynamic characteristics negatively impact the ability to maintain the slider at the prescribed flying height and introduces instability with regard to pitch and roll control. Accordingly, there is a need in the art for an improved disk drive in comparison to the prior art.